Cryogenic liquids and gases are well known and are used in a variety of industrial applications. A variety of structures has previously been described for storage of such cryogenic materials, separation of cryogenic gases and liquids and for cooling gases and liquids using cryogenic materials.
A search conducted in the facilities of the U.S. Patent and Trademark Office with respect to the present invention has revealed the following U.S. Pat. Nos. as the closest prior art:
______________________________________ 4,510,760 3,422,632 4,607,489 3,455,117 2,772,545 3,729,946 3,144,200 3,913,340 3,296,809 4,203,299 3,360,947 4,279,626 ______________________________________
This prior art is illustrative of prior art structures. For reasons which will become apparent below, none of this prior art discloses or suggests the apparatus of the present invention.
In the parent application, the Examiner also has cited the following U.S. Pat. Nos. as prior art:
______________________________________ 3,049,887 4,192,147 4,296,610 4,464,904 4,715,187 4,726,195 ______________________________________
Of these references, the Examiner has relied mainly on U.S. Pat. Nos. 4,296,610 (Davis) and 4,715,187 (Davis). Both of these references relate to subcoolers, whose sole purpose is to reliquify two-phase cryogenic gas, by cooling the two-phase gas with exactly the same gas bath held at near atmospheric pressure, in which state the gas is the coldest possible. As will be seen herein, these devices are structurally and functionally different from the device provided by the present invention.